It is not possible to exclude certain users from being able to update products/line items and making sure pricing strategy is honored. It would prevent the creation of quotes with bad intent, bad pricing and/or bad information.
Currently:
Within permission sets, it is only possible to prevent the creation of custom line items for HubSpot Users.
In addition, it is also not possible to restrict the access to the different type of properties and what users are able to do with them.
The request:
Big request to at least make it possible to restrict the updating of this line items or product properties to certain groups or users.
Ideally, first being able to adjust the ‘property access’ in Product properties and later on adding the permission options in the actual permission sets. Perhaps adding the option as ‘Product/line item permissions’.